1. Field of the Invention
This invention relates to high pressure radial turbines, compressors, pumps and the like and particularly to such devices having adjustable stator blades or vanes to vary the area of the throats defined between adjacent stator vanes. To operate at low specific flows, the dimensions of the stator throats must be adjusted very accurately if the desired peformance is to be achieved. Conventional arrangements comprising sliding pins or individual setting links connected to a control ring generally involve a certain amount of looseness on the vane setting, and can lead to jamming of the parts when and if high temperatures are involved.
2. Prior Art
Homersham, U.S. Pat. No. 1,187,428, relates to a centrifugal blower and the like in which the angle of each blade is adjusted, the blades each being formed with a tang fitting into a slot in a pin passing through a ring. A nut on each pin is tightened when the blade angle is set or reset to firmly hold the blade in position. The arrangement permits and requires each blade to be individually set.
Beran et al, U.S. Pat. No. 3,349,997, teaches an arrangement for adjusting diffuser blades in turbo-compressors. Each blade is attached by a pin to a rotatable ring. Rotation of the ring causes the pins to rotate which changes the blade angles.
Moskowitz et al, U.S. Pat. No. 3,736,070, teaches diffuser blades each of which is rotatable about a radial axis by movement of a ring surrounding the blades.
Balje, U.S. Pat. No. 3,963,369, teaches movable vanes in a diffuser, the position of which are adjusted by moving a ring in which the outer ends of the vanes are pivotably connected.
Swearingen, U.S. Pat. No. 3,495,921, teaches a variable nozzle turbine in which a plurality of nozzle blades are sandwiched between a piar of axially spaced concentrically-mounted rings. The blades are pivotably attached to the rings, one of the latter being rotatable while the other is fixed. Rotation of the one blade causes a change in angularity of all the blades.